The present invention relates to a lamination type inductor, and more particularly, to a lamination type inductor used for preventing noise and the like.
The conventional lamination type inductor used for preventing noise and the like has been constructed, as shown in FIG. 4, by laminating outside ferrite layers on both main surfaces of a ferrite layer 3 having a linear conductor pattern 2 extending from one end to the other. These ferrite layers 3 and outside ferrite layers 4 were laminated so as to be integral, and then sintered and then, as shown in FIG. 5, provided with outside electrodes 5 to form a lamination type inductor 1.
However, in such a lamination type inductor 1 as described above, since the conductor pattern 2 is linear, only a small inductance can be obtained. Thus, to obtain a larger inductance, a lamination type inductor 6 has been designed which is shown in FIG. 6. This inductor 6 comprises a first ferrite layer 8 on one main surface of which is formed a first conductor pattern 7 designed to be an end portion of a coil, and a second ferrite layer 11 on both main surfaces of which are formed second conductor patterns 10 corresponding to half a coil and which are connected through a through hole. First ferrite layers 8 and second ferrite layers 11 are laminated so that the first conductor pattern 7 and the second pattern 10 are connected to form a coil. With this lamination type inductor 6, a larger inductance can be obtained than with the inductor 1 shown in FIGS. 4 and 5.
But, the conventional lamination type inductor as shown in FIG. 6 requires a plurality of different conductor patterns on a plurality of ferrite layers that not only the number of printings but the number of through holes must be increased, thereby taking much time to manufacture and being subject to defects during production. Moreover, lamination of a plurality of conductor pattern causes a number of connecting points to occur on the conductor patterns to form them into coils, whereby the electric connections between the conductor patterns formed on respective ferrite layers are sometimes poor, thereby lowering reliability of the finished product.